If I open a Blender file and the UI looks weird, can I move/close the UI elements to make it look like the default?
At the top of the screen next to the layout tabs, you can click the + sign to add the layouts you are more familiar with. The default workspace is Layout which can be found by going to General > Layout.

To move around the existing workspaces, right-click a tab, and select Reorder to Front or Reorder to Back.